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SPRAY PAINTING TROUBLE SHOOTING
GUIDE
Manufacturers of Quality Coatings1300 BCCOAT (222 628)
www.bccoatings.com.au
PG NO. PROBLEM ALTERNATE TERM
3 1 Air Entrapment Craters
3 2 Bleeding Discoloration
4 3 Blistering Pimples, Bubbles, Bumps
4 4 Blushing Milkiness
5 5 Chalking Fading, Oxidation, Weathering
5 6 Colour Mismatch Wrong colour
6 7 Cracking Checking, Crazing, Splitting, Alligatoring, Crows feet
7 8 Dust Contamination Dirt in finish
8 9 Fish eyes Silicon Contaminations, Cratering
8 10 Lifting Shriveling, Swelling, Raising ,Alligatoring, Wrinkling
9 11 Loss of Gloss Hazing Dulling, Die-back, Matting, Weathering
9 12 Mottling Streaking, Tiger / Zebra Stripes, Floating, Flooding
10 13 Orange Peel Poor Flow, Texture
10 14 Peeling De-lamination, Flaking
11 15 Pin Holes Holes
11 16 Runs / Sags Hangers, Curtains, Signatures
12 17 Sanding Marks Streaked Finish, Sand scratches
12 18 Sand Scratches Swelling, Sinking, Shrinkage
13 19 Seediness Gritty, Dirty, Grainy, Speckled
13 20 Shrinkage Bull eyes, Ringing, Edge Mapping
14 21 Slow Film Slow Dry
14 22 Solvent Popping Boiling, Blowing, Gassing
15 23 Wave Uneven surface
You may come across problems like some of these below sometimes which can be caused from anything from the weather to misuse of the product.
You can read about the causes of these problems, how to fix them and how to prevent them in the future by reading this troubleshooting guide.
2
Air EntrapmentDescription
Small crater like openings in or on the paint film.
Cause
Trapped or buried air pockets in the wet paint film that rise to the surface and “burst’ causing small craters. Lack of atomisation is the cause of air entrapment and may be due to one or more of the following:
• Spray gun travel too slow.
• Spray gun distance too close.
• Air pressure to low.
• Improper spray gun setup.
Repair
1. Sand with 2000 or finer grit sand paper, then compound and polish to restore gloss.
2. Or, sand smooth and refinish.
Prevention
• Maintain correct spray gun speed.
• Maintain correct spray gun distance.
• Use the recommended air pressure.
• Use the correct air cap / nozzle / needle recommended for clear coats.
Note: Some cases of air entrapment may have an appearance very similar to solvent pop or dust contamination. However, air entrapment normally occurs when the film is still wet and can be removed with compounding procedures. On the other hand, solvent pop will appear after the film is “skinned over” and when sanded will have pinholes. Dust contamination will appear while the film is drying but still “tacky.” These craters, under close examination, will have a speck of dirt in the centre of the crater.
BleedingDescription
A red or yellow discoloration in the topcoat colour.
Cause
Solvent in the new topcoat dissolves soluble dyes or pigments in the original finish, allowing them to seep into and discolour the new topcoat.
Repair
1. Allow colour to cure isolate with two component undercoat(s) and refinish.
2. Or, remove original paint film and refinish.
Prevention
Isolate suspected bleeding finish by applying a two-component surfacer clear sealer. Allow to cure and then apply desired topcoat.
Large wet droplets
Air rises from �lm leaving a small crater
Old pigment dissolves into new �nish
Old �nish
Pink
New �nish Solvent Red pigmentWhite pigment
1
2
AKA: Craters
AKA: Discoloration
3
BlisteringDescription
Swelled areas appearing as pimples or bubbles in the topcoat film, often months after application.
Cause
• Moisture trapped beneath the paint film due to:
> Contaminated airlines or
> Spraying in extreme high humidity conditions
• Using a poor grade and / or too fast evaporating thinner / reducer for spray conditions.
• Too long a flash time between coats.
• Improper dry time of undercoats before top coating.
• Painting over grease or oil.
Repair
Remove affected area by sanding and refinish.
Prevention
• Drain moisture from compressor and airlines regularly. Allow additional flash time between coats and / or add retarder when spraying in humid conditions, or spray at times of low humidity when possible.
• Select proper thinner / reducer for spray conditions.
• Apply materials according to product recommendations, allowing sufficient flash time between coats but not too long.
• Allow undercoats to thoroughly dry / cure before top coating.
• Clean and prep substrate using recommended products and procedures.
• Ensure suitable filtration is installed.
BlushingDescription
A milky grey cloud appears on the surface of the paint film immediately or shortly after application.
Cause
• When spraying during humid conditions, air from the spray gun and solvent evaporation lowers the substrate temperature below the dew point, causing moisture in the air to condense in or on the paint film. The condition is aggravated when too fast drying or unbalanced thinner / reducer is used.
Repair
If the finish has dried, minor blushing may be corrected by compounding or polishing.
Prevention
• Always use appropriate solvent and thin / reduce material according to Manufacturer’s directions.
• Select proper thinner / reducer for spray condition.
Moisture accumulates and expands, pushing up paint �lm.
UndercoatTopcoat Trapped moisture
As thinner evaporates, moisture in theair condenses in the paint �lm.
Solvent
Moisture
3
4
AKA: Pimples, Bubbles, Bumps
AKA: Milkiness
Gerson Tack Cloths
These soft mesh cotton cloths contour to the surface ensuring removal of particulates without harmful residue. Wax and silicone free.
Colour SKU Pack Size
Blue Economy GACCSEL.132 Pack of 12
Orange Deluxe GACCSEL.131 Pack of 12
4
ChalkingDescription
A chalky white appearance on the surface of the paint film.
Cause
• Pigment is no longer held and protected by resin, resulting in a powder-like surface and lack of gloss due to:
> Natural weathering of the paint film.
> Improper application of paint material.
> Using generic thinner / reducer and / or hardener in the paint material.
Repair
1. Compound to remove oxidation and polish to restore gloss.
2. Or, sand to remove “weathered” paint film and refinish.
Prevention
• Occasional polishing or waxing will remove oxidation from the finish.
• Thoroughly stir, shake or agitate all paint materials.
• Use the recommended thinner / reducer, hardener, and measure accurately.
Colour MismatchDescription
The colour that you want is not the same that you have sprayed.
Cause
• Received the wrong colour
• Ordered the wrong colour
• Ordered the right colour, but the wrong source. ie Dulux instead of Wattyl
• Paint has not been stirred
• Applied too much paint on the surface & floatation has occurred
• Re-coated the surface on several times
• Be aware of metamerism
• Shadows
Repair
1. Sand back with 400 Grit and respray
2. If resprayed several times, you may have to recolour match
Prevention
• Always check the spray out on the side of the paint tin that it matches by sight, that the name of the colour and the source is correct
• Always open the tin and stir well before using
• Do not over apply paint to surface
• Have spray gun set up correctly
• Check colour under Australian standards lights
Pigment and Flake protected by clear resin.
When clear resin wears away, pigmentand �ake are exposed to the environment
and deteriorate rapidly.
Clear ResinPigment Flake
5
6
AKA: Fading, Oxidation, Weathering
AKA: Wrong colour
5
CrackingDescription
Cracks or lines of various lengths and widths in the topcoat finish often resembling the cracking of dried mud.
Cause
• Excessive film thickness of the undercoat and / or topcoat.
• Refinishing over a previously crazed / cracked surface.
• Insufficient flash time between coats and / or force drying undercoats using air from the spray gun.
• Mixing incorrectly or using too much hardener.
• Paint ingredients not thoroughly stirred or agitated.
• Break down of finish due to prolonged exposure to sunlight, moisture, and extreme temperature changes.
Repair
Remove all cracked paint film and refinish.
Prevention
• Apply all materials following manufacturer’s direction.
• Completely remove crazed / cracked finishes before refinishing.
• Do not over force dry undercoats.
• Mix ingredients thoroughly using the recommended additives.
• Add each component in proper sequence following the recommended mixing ratio.
• Stir or agitate materials thoroughly before use.
• Use correct two-component undercoat and topcoat system to provide maximum gloss and durability.
• Use the recommended thinner / reducer and hardener, and then measure accurately.
Topcoat
Undercoat
Film Shrinkage
7AKA: Checking, Crazing, Spitting,
Alligatoring, Crowsfeet
Size SKU
350ml GCUPCO350ML
700ml GCUPCO700ML
1400ml GCUPCO1400ML
2300ml GCUPCO2300ML
Colad Measuring Cups
Colad Mixing Cups for paint preparation are made of a customized, high quality polypropylene. This gives the cup a very stable harshness and high clarity that guarantees the readability of the mixing ratio’s from inside out. The cups are designed for one time use. Save cleaning time using the precision printed cups.
Features:• Compatible with various paint application systems • Solvent resistant • Anti-static • Stackable to save space • Flat bottom • Precision printed with eight accurate mixing ratios• Two measuring scales
6
Dust ContaminationDescription
Foreign particles embedded in paint film.
Cause
• Inadequate cleaning of the surface to be painted.
• Dirty spraying environment.
• Inadequate air filtration or unfiltered air entering the booth.
• Dirty or unsuitable work clothes that contain dust, lint, or fibbers.
• Particles from deteriorated air supply lines.
• Dirty spray gun.
• Removing job from the spray booth before the finish is ‘dust free.
Repair
1. Sand with 2000 or finer grit sandpaper, compound and polish to restore gloss.
2. Or, sand smooth and refinish.
Prevention
• Thoroughly blow off mouldings. Wipe the surface to be painted and the masking paper with the tack rag.
• Maintain a clean working area.
• Install proper air filters. Repair any leakage found in the spray booth due to poor fitting doors, gaskets, seams or filters.
• Wear a lint free paint suit during the spray application.
• Use quality masking materials. “Wicks” found on newspaper can break away and blow into the wet paint.
• Repair or replace defective airlines.
• Properly clean and maintain spray equipment.
• Job should be kept in a clean environment until finish is “dust free
• Always strain paint.
Dust Particles
New FinishOld Finish
Dust Particles
1. Dust particles adhere to a wet or tacky �nish.
2. Dust particles become encapsulated by a wet or tacky clearcoat.
ClearcoatBasecoat
8AKA: Dirt in finish
Reusable Filters
SKU: GPAINTFIRPF5000
Used where fine to very fine filtration is needed and can be used up to 10 times. These filters are solvent resistant but will eventually soften.
2Spray Gun Cleaning Kit
SKU: GGUNPASEL.11
The Gun Cleaning Kit comes in a blister pack and is made up of 6 assorted spray gun cleaning brushes, sachet of petroleum jelly and cleaning sticks.
Top quality solvent resistant brushes (various types) to suit all types of spray guns.
Includes:
• 6 cleaning brushes
• Petroleum jelly
• Cleaning sticks
7
FisheyesDescription
Small circular, crater-like openings that appear during or shortly after the spray application.
Cause
• Spraying over surfaces contaminated with oil, wax, silicone, grease, etc.
• Use of thinner / reducer in place of a solvent cleaner.
• Spraying over previously repaired areas containing “fisheye eliminator additive.
• Contaminations from airlines, food or air born.
Repair
1. Remove wet paint film with solvent, clean and refinish.
2. Add the recommended fisheye eliminator and respray the affected area.
3. If the paint has dried, wash with wax and grease remover then sand to a smooth finish below the fisheye cratering. Dust down wash with wax and grease remover and refinish.
Prevention
• Use fisheye eliminator that is specifically recommended for the topcoat.
• Install an air filtering system that removes and prevents oil and moisture contamination.
• Maintain air supply by draining, cleaning and changing filter on a routine basis.
LiftingDescription
The existing paint film shrivels or swells during new finish application or drying.
Cause
• Solvents in a newly applied product attack the previous finish causing wrinkling, raising, or puckering of the paint film due to:
> Re-coating urethanes that are not fully cured due to the lack of hardener.
> Re-coating over enamels.
Repair
Remove and refinish.
Prevention
• Check questionable finishes by rubbing a small inconspicuous area with a shop towel saturated with lacquer thinner finishes susceptible to lifting will soften, swell or shrivel as lacquer thinner is applied. If any of these reactions occur the coating must be removed before re-coating.
New Finish
Old Finish
OilSilicone
New Finish
New Finish
Solvent
Old Finish
Old Finish
Solvent penetration causes lifting ofimproperly cured �nishes
9
10
AKA: Silicone Contamination, Cratering
AKA: Wrinkling, Raising, Alligatoring, Shriveling, Swelling
Motor Guard M-30 Sub-Micronic Inline Filter
SKU: GFILTERM30
• Eliminates paint failures caused by particulate, moisture and oil aerosol contaminates as small as .01 micron
• Extends the life of your tools by protecting bearings and precision parts from dirty, oily, watery contaminants
• Increases the efficiency and tip life of your plasma cutter by removing moisture and oil aerosols from your compressed air line
DeVilbiss Airline Disposable Filters
SKU: GFILTERHAF-507
• High efficiency action traps, water, oil & dirt
• Incorporates multi-layered, high efficiency filter pads
• Minimal pressure drop and long service life.
• Tough, solvent resistant Delrin housing with 1/4” threads
• 50 grams
8
Loss of GlossDescription
A dulling of the gloss as the film dries.
Cause
• Topcoat applied in heavy, wet coats.
• Inadequate flash time between coats.
• Insufficient drying / curling of undercoats before applying topcoats.
• Using too fast evaporating thinner / reducer for spray conditions.
• Improper cleaning of the substrate.
• Insufficient air movement during and after application.
• Spraying over a deteriorated or solvent sensitive substrate finish without proper priming or sealing procedures.
Repair
1. Allow finish to cure thoroughly, compound or polish to restore gloss.
2. Or, sand and refinish.
Prevention
• Apply the topcoat according to manufacturer’s directions using the recommended gun setup and air pressure.
• Allow all coatings sufficient flash between coats.
• Apply sufficient number of coats to achieve recommended proper film thickness. Check with film thickness gauge if possible.
• Allow undercoats to thoroughly dry / cure before top coating.
• Select recommended thinner / reducer based on temperature, humidity, air movement, and size of repair.
• Clean substrate thoroughly before and after sanding.
• For air dry situations: (1) allow exhaust fan to run 40 minutes or longer after spraying; (2) open booth doors after finish is dust free.
• For maximum holdout, use premium abrasives.
MottlingDescription
A streaked spotty, or striped appearance in a metallic colour.
Cause
• An uneven distribution of metallic flake caused by:
> Using a spray gun that gives an unbalanced spray pattern.
> Improper application technique such as tilting the spray gun during application, causing the spray pattern to become heavy at the top or bottom.
• Holding the gun too close to the surface (flooding).
• Uneven spray pattern overlap.
• Omitting / improper use of mist coats.
• Too much thinner / reducer. Colour over thinned / reduced.
• Applying clear coat to a basecoat that has not thoroughly flashed off.
Repair
1. Reapply a high pressure mist coat, while previous coat is still wet.
2. Or, allow colour to flash, and then apply a low pressure mist coat.
3. Finishes that have dried must be sanded and refinished.
Prevention
• Use recommended spray gun, including fluid tip and air cap for the material being sprayed. Always adjust the gun for best atomisation and balanced spray pattern before paint application.
• Use the correct ratio of thinner / reducer
• Allow basecoat proper flash off before clear coating.
Gloss Loss of Gloss
Uneven distribution of metallic �ake causesstreaks and mottling
New Finish
Unbalanced spray pattern
11
12
AKA: Hazing, Dulling, Dieback, Matting
AKA: Streaking, Tiger/Zebra Stripes, Floating, Flooding
9
Orange PeelDescription
Paint film having an uneven texture that resembles the skin of an orange.
Cause
• Under reduction and / or air pressure too low.
• Thinner / reducer evaporates too fast for spray conditions.
• Excessive film thickness or piling on of heavy wet coats.
• Improper spray gun set-up.
• Improper painting technique.
Repair
1. Compound or polish to reduce surface texture.
2. Or, sand smooth with 2000 or finer grit sandpaper, compound and polish to restore gloss.
3. Or, sand smooth and refinish.
Prevention
• Use proper reduction ratio and spray at recommended air pressure.
• Select recommended thinner / reducer based on temperature, humidity, air movement, and size of job.
• Avoid heavy coats and excessive film thickness.
• Use recommended spray gun, fluid tip and air cap for the material being sprayed. Always adjust the gun for best atomisation and balanced spray pattern before paint application.
• During paint application, hold the gun perpendicular and parallel to the surface. Adjust speed of pass, pattern overlap, and distance from the panel to achieve the desired appearance.
• Select recommended Hardener based on temperature, humidity, air movement, and size of job.
PeelingDescription
A loss of adhesion or separation of the paint film from the substrate.
Cause
• Improper preparation of the substrate (sanding and cleaning).
• Omitting or applying an incompatible undercoat to a specific substrate (e.g. aluminium, galvanized, plastics, etc.).
• Exceeding the products maximum re-coat time.
• Insufficient film thickness of undercoat, or topcoat.
• Using more than recommended fish-eye eliminator.
• Incompatible clear coat.
• To little or to much hardener.
Repair
1. Remove the finish, and refinish.
Prevention
• Clean and prepare all substrates according to product recommendations.
• Use the recommended undercoat (primer) for the substrate being finished.
• Re-coat all products within their recommended minimum and maximum re-coat time.
• Apply a sufficient number of coats to obtain the recommended film thickness.
• Use only recommended / compatible products.
• Adhesion ‘promoter’ should only be used when specifically recommended.
Clear Resin13
14
Alternative symptoms: Poor Flow, Texture
AKA: Flaking, De-laminating
10
Runs / SagsCoatings that fail to adhere uniformly, causing beads, droplets, or slippage of the total film.
Cause
• Over reduction and / or too slow evaporating thinner / reducer.
• Applying paint materials without proper flash time between coats.
• Applying excessive wet coats due to:
> Holding the gun too close to the surface;
> Slow gun speed;
> Double coating.
• Air pressure too low during spray application.
• Improper spray gun set-up or an unbalanced spray pattern.
• Material and / or substrate temperature too cold.
Repair
1. Remove the wet paint film with solvent, clean and refinish.
2. Or, after finish is completely dry. Remove excess paint by sanding with 2000 or finer grit sandpaper, compound and polish to restore gloss.
3. Or sand smooth and refinish.
Prevention
• Mix according to product directions. Select recommended solvent and hardeners for spray conditions based on temperature, humidity, air movement.
• Spray medium wet coats and allow sufficient flash time between coats.
• Adjust the spray gun for the best atomisation and balanced spray pattern before paint application. Hold the spray gun perpendicular and parallel to the panel. Adjust speed of pass, pattern overlap, and distance from the panel until the desired results are achieved.
• Set air pressure at the gun.
• Use recommended spray gun, including fluid tip and air cap combination.
• Allow paint material and substrate to reach room temperature before application.
New Finish
Old Finish
16AKA: Hangers, Curtains, Signatures
Pin HolesSmall holes or bubbles located in or on top of putties or body fillers. (Mainly found in the Automotive industry)
Cause
• Air or gas bubbles become trapped inside putty or filler during mixing or product application. These bubbles are exposed during the sanding process, creating small holes or craters in the surface. Air or gas is trapped when:
> Filler and hardener are mixed together using a “whipping” motion (fast circular motion);
> Adding too much hardener;
> Applying heavy thick coats producing excessive heat, causing gas bubbles to form inside the product as it cures.
• Poor quality substrate
Repair
Apply a thin layer of polyester glazing putty (properly catalyzed and mixed), sand smooth and continue the repair process.
Prevention
• Mix putty / filler components by folding together and pressing down to eliminate air pockets
• Apply putty / filler in thin coats, do not exceed manufacturer’s recommended total film thickness
• Follow manufacturer’s recommendation of correct ratio of putty/filler to
15AKA: Bubbles, Air pockets
11
Sand ScratchesDescription
Visible lines or marks in the paint film that follow the direction of the sanding process.
Cause
• Sanding the substrate with too coarse grit sandpaper.
• Insufficient dry / cure of undercoats before sanding and top coating.
• Refinishing over soft, soluble substrates.
• Using a poor grade and / or too fast evaporating thinners / reducers for spray conditions causing:
> Primer surfacer to bridge” over sand scratches;
> Topcoat to skin over,” trapping solvent which swells sensitive substrates.
• Using a solvent cleaner that is too strong for the substrate or using thinner / reducer as a surface cleaner after sanding.
Repair
1. Allow finish to dry / cure, sand smooth, compound or polish to restore gloss.
2. Or, sand and refinish.
Prevention
• Sand with recommended grit sandpaper.
• Allow undercoats to thoroughly dry / cure before sanding and top coating.
• Select recommended thinner / reducer based on temperature, humidity, air movement. Avoid “bridging” existing scratches by applying primer surfacer in thin wet coats, allowing adequate flash time between each coat.
Bridging of sandscratches due to lacquerprimer surfacer being under reduced and/or
drying too quickly.
Slow evaporating solvent in new �nish re�ows soluble lacquer primer surfacer.
Sandscratches appear in new �nish as re�owing primer surfacer �lls sandscratches
in old �nish.
BridgingPrimer Surfacer
Primer Surfacer
Primer Surfacer
Old Finish
Old Finish
Old Finish
New Finish
New Finish
Solvent
18AKA: Swelling, Sinking, Shrinkage
Sanding MarksDescription
Dark and / or streaked marks that resemble sand scratches in the paint film.
Cause
• Scratching or distorting metallic / mica flakes close to the surface of the paint film due to:
> Sanding metallic finishes prior to clear coating.
> Sanding metallic finishes prior to buffing.
Repair
1. Allow finish to dry, sand and refinish.
Prevention
• Avoid sanding metallic finishes before clear coating. If sanding is necessary apply additional colour following label direction.
• When sanding finishes confine the sanding to minor imperfections (nib sanding rather than entire panels).
Sanding swirl marks in the substrate show as lines in the top-coat.
17AKA: Streaked Finish, Sand Scratches
12
SeedinessDescription
Solid particles of various shapes and sizes embedded evenly throughout the paint film.
Cause
• Material not properly stirred or agitated.
• Failure to strain material.
• Using material exceeding its shelf life.
• Using generic reducers and / or hardeners.
• Using materials beyond their specified pot life.
• Using contaminated thinner / reducer or hardener.
• Using contaminated water borne products.
Repair
1. Remove the wet paint film with solvent, clean and refinish.
2. Or, sand smooth and refinish.
Prevention
• Stir or shale materials thoroughly to be sure all pigment / resin is in solution.
• Strain all undercoats and topcoats.
• Do not use material that cannot be stirred or strained. Caution. Repeated straining will not completely remove seediness.
• Use the recommended thinner / reducer and hardener and measure accurately.
• Mix only enough material that can be used within specified pot life.
• Use material as soon as possible, close and tighten container lids immediately after use.
• Do not allow thinner / reducer to come into contact with water borne products.
New Finish
Old Finish
Insoluble particles
Finish containing seediness
19AKA: Gritty, Dirty, Grainy, Speckled
ShrinkageDescription
The repaired area, feather-edge, or sand scratches become visible within hours, days or weeks after the repair is completed.
Cause
• Top coating before undercoats have thoroughly dried / cured.
• Undercoats applied excessively wet with inadequate flash time between coats.
• Undercoats under reduced.
• Using a poor grade and / or too fast evaporating thinner / reducer for spray conditions.
• Finishing over body filler that has not thoroughly cured.
• Using too strong solvent cleaner or using thinner / reducer as a surface cleaner.
Repair
1. Allow the affected area to thoroughly dry / cure, sand and refinish
2. If additional filling is necessary, apply a primer surfacer, sand smooth and refinish.
Prevention
• Allow undercoats to thoroughly dry / cure before sanding and / or top coating.
• Thin or reduce undercoats according to product label directions. Apply in thin wet coats allowing adequate flash time between coats to avoid ‘bridging’ scratches.
• Select recommended thinner / reducer based on temperature, humidity, air movement, and size of repair.
• Follow body filler manufactures recommended cure time.
• Use solvent cleaner designated for either lacquer soluble or cured enamel / urethane insoluble substrate.
Topcoat Solvent
Undercoat
Old FinishBody Filler
Film shrinks as solvent evaporates
Substrate
20AKA: Bulls Eyes, Ringing, Edge Mapping
13
Solvent PoppingDescription
Small bubbles, pinholes, crater-like openings in or on the paint film.
Cause
• Liquid solvent (thinners / reducers) becomes “trapped” in the paint film when the surface layer skins over too quickly, preventing their evaporation into the atmosphere. Solvents that vaporize within the paint film leave bubbles, pinholes or craters as they push through and “pop’ the surface. Solvents can be trapped due to:
> Thinner / reducer evaporating too fast for spraying conditions.
> Inadequate flash time between coats.
> Excessive film thickness or piling on” of heavy / wet coats.
> Not sufficient air movement to strip out solvents.
> Excessive purge / flash time before force drying.
> Board manufacturing problem.
Repair
1. Allow finish to thoroughly dry/cure, sand 320 then 400 Grit and refinish. Inspect surface carefully to ensure all craters have been removed.
2. Severe popping will require removal of the affected film. Prime, seal and re-coat, as necessary.
Prevention
• Select recommended thinner / reducer based on temperature, humidity, air movement and size of Job.
• Allow for proper flash time between coats.
• Avoid “piling on” or double wet coats.
• Check air movement over the surface being painted.
• Avoid extended purge / flash time before force drying.
Solvent
Old Finish New Finish
Solvent vaporizes within paint �lm then burst through the surface
Surface skins over
22AKA: Boiling, Blowing
Colour Ratio SKU
Blue 2:1 GBCCSTICKBLUE2:1
Red 4:1 GBCSTICKRED4:1
Soft FilmDescription
The paint film is soft to the touch, and will fingerprint or water spot within hours / days after application.
Cause
• Applying undercoat and / or topcoat excessively wet.
• Insufficient dry time between coats.
• Improper shop ventilation or heating.
• Adding too much or too little hardener to the paint material.
• Using the incorrect thinner / reducer for spray conditions.
Repair
1. Allow additional dry time.
2. Or, force dry following temperature and time recommendations.
3. Or, remove soft paint film and refinish.
Prevention
• Use recommended spray gun, fluid tip and air cap for the material being sprayed. Always adjust the gun for best atomisation and balance spray pattern before paint application.
• Allow sufficient flash time between coats.
• Maintain shop temperature. Properly cure.
• Use the recommended hardener and measure accurately.
• Select appropriate thinner / reducer based on temperature, humidity, air movement, and size. Allow addition flash time when spraying in high humidity or low temperature / high humidity conditions.
21AKA: Slow Dry
BC’s Measuring Stick
BC’s measuring sticks make it easy to work out the mixing ratios of paint and hardener.
14
WaveDescription
The surface of the paint contains irregular grooves or ridges resembling waves.
Cause
• Excessive film thickness or “piling on” of heavy wet coats.
• The use of too much air Pressure.
• Wrong grade board.
• Placing a newly painted finish in hot sun too soon after spraying.
• Using lacquer thinner to reduce synthetic enamel.
• Spraying in extreme hot, humid weather conditions.
• Under reduced and / or too fast evaporating thinner / reducer for spray conditions.
• Force drying of air-dry enamels without the recommended additives.
Repair
Allow finish to thoroughly dry / cure, sand 320 then 400 grit and refinish.
Prevention
• Avoid “piling on” or double wet coats.
• Use the proper reduction ratio and spray at recommended air pressure.
• Use correct board.
• Keep newly painted finish away from direct sunlight until finish has dried / cured.
• Use reducer that is specifically recommended for the topcoat / weather.
• Use the proper reduction ratio and spray at recommended air pressure.
Lower wet coats are not able to release their solvents when the surface layer “skins
over” too quickly
Surface layer shrinks while underlying material remains �uid
OxygenSolvent
23AKA: Wrinkling, Crinkling, Puckering
Cool - Moderate
Cool - Moderate
Medium - Hot
Medium - Hot
Hot - Severe
Hot - Severe
40
35
30
25
2010
15
40
35
30
25
2010
15
PE230 / PE235 POLYESTER WHITE UNDERCOAT
GUIDETEMPERATURE
POLYESTER
GUIDETEMPERATUREPOLYURETHANE
PE100THINNER PE105 PE110
UT900 UT903HARDENER
THINNER UT100 UT101, UT900S
UT935F UT935M UT935S
UT935 SUMMER
UT900, UT925, UT935 POLYURETHANE GLOSS FINISHES ONLY
15
Glass | Timber | Metal | Plastics | ConcreteFurniture | Automotive | Marine | Aviation | UV Protective
1300 222 628www.bccoatings.com.au
